drivers/serial/uart_xmc4xxx.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Copyright (c) 2020 Linumiz
  * Author: Parthiban Nallathambi <parthiban@linumiz.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 #define DT_DRV_COMPAT	infineon_xmc4xxx_uart

 #include <xmc_uart.h>
 #include <zephyr/drivers/pinctrl.h>
 #include <zephyr/drivers/uart.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/irq.h>

 struct uart_xmc4xxx_config {
 	XMC_USIC_CH_t *uart;
 	const struct pinctrl_dev_config *pcfg;
 	uint8_t input_src;
 #if defined(CONFIG_UART_INTERRUPT_DRIVEN)
 	uart_irq_config_func_t irq_config_func;
 	uint8_t irq_num;
 #endif
 	uint8_t fifo_start_offset;
 	uint8_t fifo_tx_size;
 	uint8_t fifo_rx_size;
 };

 struct uart_xmc4xxx_data {
 	XMC_UART_CH_CONFIG_t config;
 #if defined(CONFIG_UART_INTERRUPT_DRIVEN)
 	uart_irq_callback_user_data_t user_cb;
 	void *user_data;
 	uint8_t service_request;
 #endif
 };

 static int uart_xmc4xxx_poll_in(const struct device *dev, unsigned char *c)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;
 	bool fifo_empty;

 	if (config->fifo_rx_size > 0) {
 		fifo_empty = XMC_USIC_CH_RXFIFO_IsEmpty(config->uart);
 	} else {
 		fifo_empty = !XMC_USIC_CH_GetReceiveBufferStatus(config->uart);
 	}
 	if (fifo_empty) {
 		return -1;
 	}

 	*c = (unsigned char)XMC_UART_CH_GetReceivedData(config->uart);

 	return 0;
 }

 static void uart_xmc4xxx_poll_out(const struct device *dev, unsigned char c)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;

 	/* XMC_UART_CH_Transmit() only blocks for UART to finish transmitting */
 	/* when fifo is not used */
 	while (config->fifo_tx_size > 0 && XMC_USIC_CH_TXFIFO_IsFull(config->uart)) {
 	}
 	XMC_UART_CH_Transmit(config->uart, c);
 }

 #define MAX_FIFO_SIZE 64
 static int uart_xmc4xxx_init(const struct device *dev)
 {
 	int ret;
 	const struct uart_xmc4xxx_config *config = dev->config;
 	struct uart_xmc4xxx_data *data = dev->data;
 	uint8_t fifo_offset = config->fifo_start_offset;

 	data->config.data_bits = 8U;
 	data->config.stop_bits = 1U;

 	XMC_UART_CH_Init(config->uart, &(data->config));

 	if (config->fifo_tx_size > 0) {
 		/* fifos need to be aligned on fifo size */
 		fifo_offset = ROUND_UP(fifo_offset, BIT(config->fifo_tx_size));
 		XMC_USIC_CH_TXFIFO_Configure(config->uart, fifo_offset, config->fifo_tx_size, 1);
 		fifo_offset += BIT(config->fifo_tx_size);
 	}

 	if (config->fifo_rx_size > 0) {
 		/* fifos need to be aligned on fifo size */
 		fifo_offset = ROUND_UP(fifo_offset, BIT(config->fifo_rx_size));
 		XMC_USIC_CH_RXFIFO_Configure(config->uart, fifo_offset, config->fifo_rx_size, 0);
 		fifo_offset += BIT(config->fifo_rx_size);
 	}

 	if (fifo_offset > MAX_FIFO_SIZE) {
 		return -EINVAL;
 	}

 	/* Connect UART RX to logical 1. It is connected to proper pin after pinctrl is applied */
 	XMC_UART_CH_SetInputSource(config->uart, XMC_UART_CH_INPUT_RXD, 0x7);

 	/* Start the UART before pinctrl, because the USIC is driving the TX line */
 	/* low in off state */
 	XMC_UART_CH_Start(config->uart);

 	ret = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
 	if (ret < 0) {
 		return ret;
 	}
 	/* Connect UART RX to the target pin */
 	XMC_UART_CH_SetInputSource(config->uart, XMC_UART_CH_INPUT_RXD,
 				   config->input_src);

 #if defined(CONFIG_UART_INTERRUPT_DRIVEN)
 	config->irq_config_func(dev);
 #endif

 	return 0;
 }

 #if defined(CONFIG_UART_INTERRUPT_DRIVEN)

 static void uart_xmc4xxx_isr(void *arg)
 {
 	const struct device *dev = arg;
 	struct uart_xmc4xxx_data *data = dev->data;

 	if (data->user_cb) {
 		data->user_cb(dev, data->user_data);
 	}
 }

 static int uart_xmc4xxx_fifo_fill(const struct device *dev, const uint8_t *tx_data, int len)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;
 	int i = 0;

 	for (i = 0; i < len; i++) {
 		bool fifo_full;

 		XMC_UART_CH_Transmit(config->uart, tx_data[0]);
 		if (config->fifo_tx_size == 0) {
 			return 1;
 		}

 		fifo_full = XMC_USIC_CH_TXFIFO_IsFull(config->uart);
 		if (fifo_full) {
 			return i + 1;
 		}
 	}
 	return i;
 }

 static int uart_xmc4xxx_fifo_read(const struct device *dev, uint8_t *rx_data, const int size)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;
 	int i;

 	for (i = 0; i < size; i++) {
 		bool fifo_empty;

 		if (config->fifo_rx_size > 0) {
 			fifo_empty = XMC_USIC_CH_RXFIFO_IsEmpty(config->uart);
 		} else {
 			fifo_empty = !XMC_USIC_CH_GetReceiveBufferStatus(config->uart);
 		}
 		if (fifo_empty) {
 			break;
 		}
 		rx_data[i] = XMC_UART_CH_GetReceivedData(config->uart);
 	}
 	return i;
 }

 static void uart_xmc4xxx_irq_tx_enable(const struct device *dev)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;
 	const struct uart_xmc4xxx_data *data = dev->data;

 	if (config->fifo_tx_size > 0) {
 		/* wait till the fifo has at least 1 byte free */
 		while (XMC_USIC_CH_TXFIFO_IsFull(config->uart)) {
 		}
 		XMC_USIC_CH_TXFIFO_EnableEvent(config->uart,
 					       XMC_USIC_CH_TXFIFO_EVENT_CONF_STANDARD);
 	} else {
 		XMC_USIC_CH_EnableEvent(config->uart, XMC_USIC_CH_EVENT_TRANSMIT_BUFFER);
 	}
 	XMC_USIC_CH_TriggerServiceRequest(config->uart, data->service_request);
 }

 static void uart_xmc4xxx_irq_tx_disable(const struct device *dev)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;

 	if (config->fifo_tx_size > 0) {
 		XMC_USIC_CH_TXFIFO_DisableEvent(config->uart,
 						XMC_USIC_CH_TXFIFO_EVENT_CONF_STANDARD);
 	} else {
 		XMC_USIC_CH_DisableEvent(config->uart, XMC_USIC_CH_EVENT_TRANSMIT_BUFFER);
 	}
 }

 static int uart_xmc4xxx_irq_tx_ready(const struct device *dev)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;

 	if (config->fifo_tx_size > 0) {
 		return !XMC_USIC_CH_TXFIFO_IsFull(config->uart);
 	} else {
 		return XMC_USIC_CH_GetTransmitBufferStatus(config->uart) ==
 			XMC_USIC_CH_TBUF_STATUS_IDLE;
 	}
 }

 static void uart_xmc4xxx_irq_rx_enable(const struct device *dev)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;
 	uint32_t recv_status;

 	if (config->fifo_rx_size > 0) {
 		XMC_USIC_CH_RXFIFO_Flush(config->uart);
 		XMC_USIC_CH_RXFIFO_SetSizeTriggerLimit(config->uart, config->fifo_rx_size, 0);
 #if CONFIG_UART_XMC4XXX_RX_FIFO_INT_TRIGGER
 		config->uart->RBCTR |= BIT(USIC_CH_RBCTR_SRBTEN_Pos);
 #endif
 		XMC_USIC_CH_RXFIFO_EnableEvent(config->uart,
 					       XMC_USIC_CH_RXFIFO_EVENT_CONF_STANDARD |
 					       XMC_USIC_CH_RXFIFO_EVENT_CONF_ALTERNATE);
 	} else {
 		/* flush out any received bytes while the uart rx irq was disabled */
 		recv_status = XMC_USIC_CH_GetReceiveBufferStatus(config->uart);
 		if (recv_status & USIC_CH_RBUFSR_RDV0_Msk) {
 			XMC_UART_CH_GetReceivedData(config->uart);
 		}
 		if (recv_status & USIC_CH_RBUFSR_RDV1_Msk) {
 			XMC_UART_CH_GetReceivedData(config->uart);
 		}

 		XMC_USIC_CH_EnableEvent(config->uart, XMC_USIC_CH_EVENT_STANDARD_RECEIVE |
 						      XMC_USIC_CH_EVENT_ALTERNATIVE_RECEIVE);
 	}
 }

 static void uart_xmc4xxx_irq_rx_disable(const struct device *dev)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;

 	if (config->fifo_rx_size > 0) {
 		XMC_USIC_CH_RXFIFO_DisableEvent(config->uart,
 						XMC_USIC_CH_RXFIFO_EVENT_CONF_STANDARD |
 						XMC_USIC_CH_RXFIFO_EVENT_CONF_ALTERNATE);
 	} else {
 		XMC_USIC_CH_DisableEvent(config->uart, XMC_USIC_CH_EVENT_STANDARD_RECEIVE |
 						       XMC_USIC_CH_EVENT_ALTERNATIVE_RECEIVE);
 	}
 }

 static int uart_xmc4xxx_irq_rx_ready(const struct device *dev)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;

 	if (config->fifo_rx_size > 0) {
 		return !XMC_USIC_CH_RXFIFO_IsEmpty(config->uart);
 	} else {
 		return XMC_USIC_CH_GetReceiveBufferStatus(config->uart);
 	}
 }

 static void uart_xmc4xxx_irq_callback_set(const struct device *dev,
 					  uart_irq_callback_user_data_t cb, void *user_data)
 {
 	struct uart_xmc4xxx_data *data = dev->data;

 	data->user_cb = cb;
 	data->user_data = user_data;
 }

 #define NVIC_ISPR_BASE 0xe000e200u
 static int uart_xmc4xxx_irq_is_pending(const struct device *dev)
 {
 	const struct uart_xmc4xxx_config *config = dev->config;
 	uint32_t irq_num = config->irq_num;
 	uint32_t setpend;

 	/* the NVIC_ISPR_BASE address stores info which interrupts are pending */
 	/* bit 0 -> irq 0, bit 1 -> irq 1,...  */
 	setpend = *((uint32_t *)(NVIC_ISPR_BASE) + irq_num / 32);
 	irq_num = irq_num & 0x1f; /* take modulo 32 */
 	return (setpend & BIT(irq_num)) > 0;
 }
 #endif

 static const struct uart_driver_api uart_xmc4xxx_driver_api = {
 	.poll_in = uart_xmc4xxx_poll_in,
 	.poll_out = uart_xmc4xxx_poll_out,
 #if defined(CONFIG_UART_INTERRUPT_DRIVEN)
 	.fifo_fill = uart_xmc4xxx_fifo_fill,
 	.fifo_read = uart_xmc4xxx_fifo_read,
 	.irq_tx_enable = uart_xmc4xxx_irq_tx_enable,
 	.irq_tx_disable = uart_xmc4xxx_irq_tx_disable,
 	.irq_tx_ready = uart_xmc4xxx_irq_tx_ready,
 	.irq_rx_enable = uart_xmc4xxx_irq_rx_enable,
 	.irq_rx_disable = uart_xmc4xxx_irq_rx_disable,
 	.irq_rx_ready = uart_xmc4xxx_irq_rx_ready,
 	.irq_callback_set = uart_xmc4xxx_irq_callback_set,
 	.irq_is_pending = uart_xmc4xxx_irq_is_pending,
 #endif
 };

 #define USIC_IRQ_MIN  84
 #define USIC_IRQ_MAX  101
 #define IRQS_PER_USIC 6

 #if defined(CONFIG_UART_INTERRUPT_DRIVEN)
 #define XMC4XXX_IRQ_HANDLER(index)                                                         \
 static void uart_xmc4xxx_irq_setup_##index(const struct device *dev)                       \
 {                                                                                          \
 	const struct uart_xmc4xxx_config *config = dev->config;                            \
 	struct uart_xmc4xxx_data *data = dev->data;                                        \
 											   \
 	__ASSERT(config->irq_num >= USIC_IRQ_MIN && config->irq_num <= USIC_IRQ_MAX,       \
 		 "Invalid irq number\n");                                                  \
 											   \
 	data->service_request = (config->irq_num - USIC_IRQ_MIN) % IRQS_PER_USIC;          \
 											   \
 	if (config->fifo_tx_size > 0) {                                                    \
 		XMC_USIC_CH_TXFIFO_SetInterruptNodePointer(                                \
 			config->uart, XMC_USIC_CH_TXFIFO_INTERRUPT_NODE_POINTER_STANDARD,  \
 			data->service_request);                                            \
 	} else {                                                                           \
 		XMC_USIC_CH_SetInterruptNodePointer(                                       \
 			config->uart, XMC_USIC_CH_INTERRUPT_NODE_POINTER_TRANSMIT_BUFFER,  \
 			data->service_request);                                            \
 	}                                                                                  \
                                                                                            \
 	if (config->fifo_rx_size > 0) {                                                    \
 		XMC_USIC_CH_RXFIFO_SetInterruptNodePointer(                                \
 			config->uart, XMC_USIC_CH_RXFIFO_INTERRUPT_NODE_POINTER_STANDARD,  \
 			data->service_request);                                            \
 		XMC_USIC_CH_RXFIFO_SetInterruptNodePointer(                                \
 			config->uart, XMC_USIC_CH_RXFIFO_INTERRUPT_NODE_POINTER_ALTERNATE, \
 			data->service_request);                                            \
 	} else {                                                                           \
 		XMC_USIC_CH_SetInterruptNodePointer(                                       \
 			config->uart, XMC_USIC_CH_INTERRUPT_NODE_POINTER_RECEIVE,          \
 			data->service_request);                                            \
 											   \
 		XMC_USIC_CH_SetInterruptNodePointer(                                       \
 			config->uart, XMC_USIC_CH_INTERRUPT_NODE_POINTER_ALTERNATE_RECEIVE,\
 			data->service_request);                                            \
 	}                                                                                  \
 											   \
 	IRQ_CONNECT(DT_INST_IRQ_BY_NAME(index, tx_rx, irq),                                \
 		    DT_INST_IRQ_BY_NAME(index, tx_rx, priority), uart_xmc4xxx_isr,         \
 		    DEVICE_DT_INST_GET(index), 0);                                         \
 	irq_enable(DT_INST_IRQ_BY_NAME(index, tx_rx, irq));                                \
 }

 #define XMC4XXX_IRQ_STRUCT_INIT(index)                                                             \
 	.irq_config_func = uart_xmc4xxx_irq_setup_##index,                                         \
 	.irq_num = DT_INST_IRQ_BY_NAME(index, tx_rx, irq),

 #else
 #define XMC4XXX_IRQ_HANDLER(index)
 #define XMC4XXX_IRQ_STRUCT_INIT(index)
 #endif

 #define XMC4XXX_INIT(index)						\
 PINCTRL_DT_INST_DEFINE(index);						\
 XMC4XXX_IRQ_HANDLER(index)						\
 static struct uart_xmc4xxx_data xmc4xxx_data_##index = {		\
 	.config.baudrate = DT_INST_PROP(index, current_speed)		\
 };									\
 									\
 static const struct uart_xmc4xxx_config xmc4xxx_config_##index = {	\
 	.uart = (XMC_USIC_CH_t *)DT_INST_REG_ADDR(index),		\
 	.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(index),			\
 	.input_src = DT_INST_ENUM_IDX(index, input_src),		\
 XMC4XXX_IRQ_STRUCT_INIT(index)						\
 	.fifo_start_offset = DT_INST_PROP(index, fifo_start_offset),    \
 	.fifo_tx_size = DT_INST_ENUM_IDX(index, fifo_tx_size),          \
 	.fifo_rx_size = DT_INST_ENUM_IDX(index, fifo_rx_size),          \
 };									\
 									\
 	DEVICE_DT_INST_DEFINE(index, &uart_xmc4xxx_init,		\
 			    NULL,					\
 			    &xmc4xxx_data_##index,			\
 			    &xmc4xxx_config_##index, PRE_KERNEL_1,	\
 			    CONFIG_SERIAL_INIT_PRIORITY,		\
 			    &uart_xmc4xxx_driver_api);

 DT_INST_FOREACH_STATUS_OKAY(XMC4XXX_INIT)
	/*
	* Copyright (c) 2020 Linumiz
	* Author: Parthiban Nallathambi <parthiban@linumiz.com>
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	#define DT_DRV_COMPAT infineon_xmc4xxx_uart

	#include <xmc_uart.h>
	#include <zephyr/drivers/pinctrl.h>
	#include <zephyr/drivers/uart.h>
	#include <zephyr/sys/util.h>
	#include <zephyr/irq.h>

	struct uart_xmc4xxx_config {
	XMC_USIC_CH_t *uart;
	const struct pinctrl_dev_config *pcfg;
	uint8_t input_src;
	#if defined(CONFIG_UART_INTERRUPT_DRIVEN)
	uart_irq_config_func_t irq_config_func;
	uint8_t irq_num;
	#endif
	uint8_t fifo_start_offset;
	uint8_t fifo_tx_size;
	uint8_t fifo_rx_size;
	};

	struct uart_xmc4xxx_data {
	XMC_UART_CH_CONFIG_t config;
	#if defined(CONFIG_UART_INTERRUPT_DRIVEN)
	uart_irq_callback_user_data_t user_cb;
	void *user_data;
	uint8_t service_request;
	#endif
	};

	static int uart_xmc4xxx_poll_in(const struct device dev, unsigned char c)
	{
	const struct uart_xmc4xxx_config *config = dev->config;
	bool fifo_empty;

	if (config->fifo_rx_size > 0) {
	fifo_empty = XMC_USIC_CH_RXFIFO_IsEmpty(config->uart);
	} else {
	fifo_empty = !XMC_USIC_CH_GetReceiveBufferStatus(config->uart);
	}
	if (fifo_empty) {
	return -1;
	}

	*c = (unsigned char)XMC_UART_CH_GetReceivedData(config->uart);

	return 0;
	}

	static void uart_xmc4xxx_poll_out(const struct device *dev, unsigned char c)
	{
	const struct uart_xmc4xxx_config *config = dev->config;

	/* XMC_UART_CH_Transmit() only blocks for UART to finish transmitting */
	/* when fifo is not used */
	while (config->fifo_tx_size > 0 && XMC_USIC_CH_TXFIFO_IsFull(config->uart)) {
	}
	XMC_UART_CH_Transmit(config->uart, c);
	}

	#define MAX_FIFO_SIZE 64
	static int uart_xmc4xxx_init(const struct device *dev)
	{
	int ret;
	const struct uart_xmc4xxx_config *config = dev->config;
	struct uart_xmc4xxx_data *data = dev->data;
	uint8_t fifo_offset = config->fifo_start_offset;

	data->config.data_bits = 8U;
	data->config.stop_bits = 1U;

	XMC_UART_CH_Init(config->uart, &(data->config));

	if (config->fifo_tx_size > 0) {
	/* fifos need to be aligned on fifo size */
	fifo_offset = ROUND_UP(fifo_offset, BIT(config->fifo_tx_size));
	XMC_USIC_CH_TXFIFO_Configure(config->uart, fifo_offset, config->fifo_tx_size, 1);
	fifo_offset += BIT(config->fifo_tx_size);
	}

	if (config->fifo_rx_size > 0) {
	/* fifos need to be aligned on fifo size */
	fifo_offset = ROUND_UP(fifo_offset, BIT(config->fifo_rx_size));
	XMC_USIC_CH_RXFIFO_Configure(config->uart, fifo_offset, config->fifo_rx_size, 0);
	fifo_offset += BIT(config->fifo_rx_size);
	}

	if (fifo_offset > MAX_FIFO_SIZE) {
	return -EINVAL;
	}

	/* Connect UART RX to logical 1. It is connected to proper pin after pinctrl is applied */
	XMC_UART_CH_SetInputSource(config->uart, XMC_UART_CH_INPUT_RXD, 0x7);

	/* Start the UART before pinctrl, because the USIC is driving the TX line */
	/* low in off state */
	XMC_UART_CH_Start(config->uart);

	ret = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
	if (ret < 0) {
	return ret;
	}
	/* Connect UART RX to the target pin */
	XMC_UART_CH_SetInputSource(config->uart, XMC_UART_CH_INPUT_RXD,
	config->input_src);

	#if defined(CONFIG_UART_INTERRUPT_DRIVEN)
	config->irq_config_func(dev);
	#endif

	return 0;
	}

	#if defined(CONFIG_UART_INTERRUPT_DRIVEN)

	static void uart_xmc4xxx_isr(void *arg)
	{
	const struct device *dev = arg;
	struct uart_xmc4xxx_data *data = dev->data;

	if (data->user_cb) {
	data->user_cb(dev, data->user_data);
	}
	}

	static int uart_xmc4xxx_fifo_fill(const struct device dev, const uint8_t tx_data, int len)
	{
	const struct uart_xmc4xxx_config *config = dev->config;
	int i = 0;

	for (i = 0; i < len; i++) {
	bool fifo_full;

	XMC_UART_CH_Transmit(config->uart, tx_data[0]);
	if (config->fifo_tx_size == 0) {
	return 1;
	}

	fifo_full = XMC_USIC_CH_TXFIFO_IsFull(config->uart);
	if (fifo_full) {
	return i + 1;
	}
	}
	return i;
	}

	static int uart_xmc4xxx_fifo_read(const struct device dev, uint8_t rx_data, const int size)
	{
	const struct uart_xmc4xxx_config *config = dev->config;
	int i;

	for (i = 0; i < size; i++) {
	bool fifo_empty;

	if (config->fifo_rx_size > 0) {
	fifo_empty = XMC_USIC_CH_RXFIFO_IsEmpty(config->uart);
	} else {
	fifo_empty = !XMC_USIC_CH_GetReceiveBufferStatus(config->uart);
	}
	if (fifo_empty) {
	break;
	}
	rx_data[i] = XMC_UART_CH_GetReceivedData(config->uart);
	}
	return i;
	}

	static void uart_xmc4xxx_irq_tx_enable(const struct device *dev)
	{
	const struct uart_xmc4xxx_config *config = dev->config;
	const struct uart_xmc4xxx_data *data = dev->data;

	if (config->fifo_tx_size > 0) {
	/* wait till the fifo has at least 1 byte free */
	while (XMC_USIC_CH_TXFIFO_IsFull(config->uart)) {
	}
	XMC_USIC_CH_TXFIFO_EnableEvent(config->uart,
	XMC_USIC_CH_TXFIFO_EVENT_CONF_STANDARD);
	} else {
	XMC_USIC_CH_EnableEvent(config->uart, XMC_USIC_CH_EVENT_TRANSMIT_BUFFER);
	}
	XMC_USIC_CH_TriggerServiceRequest(config->uart, data->service_request);
	}

	static void uart_xmc4xxx_irq_tx_disable(const struct device *dev)
	{
	const struct uart_xmc4xxx_config *config = dev->config;

	if (config->fifo_tx_size > 0) {
	XMC_USIC_CH_TXFIFO_DisableEvent(config->uart,
	XMC_USIC_CH_TXFIFO_EVENT_CONF_STANDARD);
	} else {
	XMC_USIC_CH_DisableEvent(config->uart, XMC_USIC_CH_EVENT_TRANSMIT_BUFFER);
	}
	}

	static int uart_xmc4xxx_irq_tx_ready(const struct device *dev)
	{
	const struct uart_xmc4xxx_config *config = dev->config;

	if (config->fifo_tx_size > 0) {
	return !XMC_USIC_CH_TXFIFO_IsFull(config->uart);
	} else {
	return XMC_USIC_CH_GetTransmitBufferStatus(config->uart) ==
	XMC_USIC_CH_TBUF_STATUS_IDLE;
	}
	}

	static void uart_xmc4xxx_irq_rx_enable(const struct device *dev)
	{
	const struct uart_xmc4xxx_config *config = dev->config;
	uint32_t recv_status;

	if (config->fifo_rx_size > 0) {
	XMC_USIC_CH_RXFIFO_Flush(config->uart);
	XMC_USIC_CH_RXFIFO_SetSizeTriggerLimit(config->uart, config->fifo_rx_size, 0);
	#if CONFIG_UART_XMC4XXX_RX_FIFO_INT_TRIGGER
	config->uart->RBCTR \|= BIT(USIC_CH_RBCTR_SRBTEN_Pos);
	#endif
	XMC_USIC_CH_RXFIFO_EnableEvent(config->uart,
	XMC_USIC_CH_RXFIFO_EVENT_CONF_STANDARD \|
	XMC_USIC_CH_RXFIFO_EVENT_CONF_ALTERNATE);
	} else {
	/* flush out any received bytes while the uart rx irq was disabled */
	recv_status = XMC_USIC_CH_GetReceiveBufferStatus(config->uart);
	if (recv_status & USIC_CH_RBUFSR_RDV0_Msk) {
	XMC_UART_CH_GetReceivedData(config->uart);
	}
	if (recv_status & USIC_CH_RBUFSR_RDV1_Msk) {
	XMC_UART_CH_GetReceivedData(config->uart);
	}

	XMC_USIC_CH_EnableEvent(config->uart, XMC_USIC_CH_EVENT_STANDARD_RECEIVE \|
	XMC_USIC_CH_EVENT_ALTERNATIVE_RECEIVE);
	}
	}

	static void uart_xmc4xxx_irq_rx_disable(const struct device *dev)
	{
	const struct uart_xmc4xxx_config *config = dev->config;

	if (config->fifo_rx_size > 0) {
	XMC_USIC_CH_RXFIFO_DisableEvent(config->uart,
	XMC_USIC_CH_RXFIFO_EVENT_CONF_STANDARD \|
	XMC_USIC_CH_RXFIFO_EVENT_CONF_ALTERNATE);
	} else {
	XMC_USIC_CH_DisableEvent(config->uart, XMC_USIC_CH_EVENT_STANDARD_RECEIVE \|
	XMC_USIC_CH_EVENT_ALTERNATIVE_RECEIVE);
	}
	}

	static int uart_xmc4xxx_irq_rx_ready(const struct device *dev)
	{
	const struct uart_xmc4xxx_config *config = dev->config;

	if (config->fifo_rx_size > 0) {
	return !XMC_USIC_CH_RXFIFO_IsEmpty(config->uart);
	} else {
	return XMC_USIC_CH_GetReceiveBufferStatus(config->uart);
	}
	}

	static void uart_xmc4xxx_irq_callback_set(const struct device *dev,
	uart_irq_callback_user_data_t cb, void *user_data)
	{
	struct uart_xmc4xxx_data *data = dev->data;

	data->user_cb = cb;
	data->user_data = user_data;
	}

	#define NVIC_ISPR_BASE 0xe000e200u
	static int uart_xmc4xxx_irq_is_pending(const struct device *dev)
	{
	const struct uart_xmc4xxx_config *config = dev->config;
	uint32_t irq_num = config->irq_num;
	uint32_t setpend;

	/* the NVIC_ISPR_BASE address stores info which interrupts are pending */
	/* bit 0 -> irq 0, bit 1 -> irq 1,... */
	setpend = ((uint32_t )(NVIC_ISPR_BASE) + irq_num / 32);
	irq_num = irq_num & 0x1f; /* take modulo 32 */
	return (setpend & BIT(irq_num)) > 0;
	}
	#endif

	static const struct uart_driver_api uart_xmc4xxx_driver_api = {
	.poll_in = uart_xmc4xxx_poll_in,
	.poll_out = uart_xmc4xxx_poll_out,
	#if defined(CONFIG_UART_INTERRUPT_DRIVEN)
	.fifo_fill = uart_xmc4xxx_fifo_fill,
	.fifo_read = uart_xmc4xxx_fifo_read,
	.irq_tx_enable = uart_xmc4xxx_irq_tx_enable,
	.irq_tx_disable = uart_xmc4xxx_irq_tx_disable,
	.irq_tx_ready = uart_xmc4xxx_irq_tx_ready,
	.irq_rx_enable = uart_xmc4xxx_irq_rx_enable,
	.irq_rx_disable = uart_xmc4xxx_irq_rx_disable,
	.irq_rx_ready = uart_xmc4xxx_irq_rx_ready,
	.irq_callback_set = uart_xmc4xxx_irq_callback_set,
	.irq_is_pending = uart_xmc4xxx_irq_is_pending,
	#endif
	};

	#define USIC_IRQ_MIN 84
	#define USIC_IRQ_MAX 101
	#define IRQS_PER_USIC 6

	#if defined(CONFIG_UART_INTERRUPT_DRIVEN)
	#define XMC4XXX_IRQ_HANDLER(index) \
	static void uart_xmc4xxx_irq_setup_##index(const struct device *dev) \
	{ \
	const struct uart_xmc4xxx_config *config = dev->config; \
	struct uart_xmc4xxx_data *data = dev->data; \
	\
	__ASSERT(config->irq_num >= USIC_IRQ_MIN && config->irq_num <= USIC_IRQ_MAX, \
	"Invalid irq number\n"); \
	\
	data->service_request = (config->irq_num - USIC_IRQ_MIN) % IRQS_PER_USIC; \
	\
	if (config->fifo_tx_size > 0) { \
	XMC_USIC_CH_TXFIFO_SetInterruptNodePointer( \
	config->uart, XMC_USIC_CH_TXFIFO_INTERRUPT_NODE_POINTER_STANDARD, \
	data->service_request); \
	} else { \
	XMC_USIC_CH_SetInterruptNodePointer( \
	config->uart, XMC_USIC_CH_INTERRUPT_NODE_POINTER_TRANSMIT_BUFFER, \
	data->service_request); \
	} \
	\
	if (config->fifo_rx_size > 0) { \
	XMC_USIC_CH_RXFIFO_SetInterruptNodePointer( \
	config->uart, XMC_USIC_CH_RXFIFO_INTERRUPT_NODE_POINTER_STANDARD, \
	data->service_request); \
	XMC_USIC_CH_RXFIFO_SetInterruptNodePointer( \
	config->uart, XMC_USIC_CH_RXFIFO_INTERRUPT_NODE_POINTER_ALTERNATE, \
	data->service_request); \
	} else { \
	XMC_USIC_CH_SetInterruptNodePointer( \
	config->uart, XMC_USIC_CH_INTERRUPT_NODE_POINTER_RECEIVE, \
	data->service_request); \
	\
	XMC_USIC_CH_SetInterruptNodePointer( \
	config->uart, XMC_USIC_CH_INTERRUPT_NODE_POINTER_ALTERNATE_RECEIVE,\
	data->service_request); \
	} \
	\
	IRQ_CONNECT(DT_INST_IRQ_BY_NAME(index, tx_rx, irq), \
	DT_INST_IRQ_BY_NAME(index, tx_rx, priority), uart_xmc4xxx_isr, \
	DEVICE_DT_INST_GET(index), 0); \
	irq_enable(DT_INST_IRQ_BY_NAME(index, tx_rx, irq)); \
	}

	#define XMC4XXX_IRQ_STRUCT_INIT(index) \
	.irq_config_func = uart_xmc4xxx_irq_setup_##index, \
	.irq_num = DT_INST_IRQ_BY_NAME(index, tx_rx, irq),

	#else
	#define XMC4XXX_IRQ_HANDLER(index)
	#define XMC4XXX_IRQ_STRUCT_INIT(index)
	#endif

	#define XMC4XXX_INIT(index) \
	PINCTRL_DT_INST_DEFINE(index); \
	XMC4XXX_IRQ_HANDLER(index) \
	static struct uart_xmc4xxx_data xmc4xxx_data_##index = { \
	.config.baudrate = DT_INST_PROP(index, current_speed) \
	}; \
	\
	static const struct uart_xmc4xxx_config xmc4xxx_config_##index = { \
	.uart = (XMC_USIC_CH_t *)DT_INST_REG_ADDR(index), \
	.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(index), \
	.input_src = DT_INST_ENUM_IDX(index, input_src), \
	XMC4XXX_IRQ_STRUCT_INIT(index) \
	.fifo_start_offset = DT_INST_PROP(index, fifo_start_offset), \
	.fifo_tx_size = DT_INST_ENUM_IDX(index, fifo_tx_size), \
	.fifo_rx_size = DT_INST_ENUM_IDX(index, fifo_rx_size), \
	}; \
	\
	DEVICE_DT_INST_DEFINE(index, &uart_xmc4xxx_init, \
	NULL, \
	&xmc4xxx_data_##index, \
	&xmc4xxx_config_##index, PRE_KERNEL_1, \
	CONFIG_SERIAL_INIT_PRIORITY, \
	&uart_xmc4xxx_driver_api);

	DT_INST_FOREACH_STATUS_OKAY(XMC4XXX_INIT)